CTL escape mutations of core protein are more frequent in strains of HBeAg negative patients with low levels of HBV DNA.

BACKGROUND: Recent studies have suggested that Cytotoxic T lymphocytes (CTL) play a key role in eliminating hepatitis B virus (HBV). OBJECTIVES: We aimed to investigate the role of mutations in different immune epitopes of hepatitis B core antigen (HBcAg) among Iranians with hepatitis B e antigen negative chronic hepatitis B (e-CHB), and asymptomatic carriers (ASCs). STUDY DESIGN: Amino acids 1-150 of HBcAg were characterized for HBV strains from 29 e-CHB patients and 48 ASCs from Iran. All patients were infected with HBV genotype D and had previously been investigated for the presence of pre-core and basic core promoter (BCP) mutants. RESULTS: Amino acid mutations of core protein were observed more frequently in HBV strains from ASCs than e-CHB patients (p=0.014). Asn(67) mutation was mutually exclusive to the combination Ile(66) and Ser(69) (P<0.001). Substitutions for Ser(21) and Thr12Ser were associated with lower serum levels of HBV DNA (p<0.001). None of the patients with mutations in HLA-A2 CTL epitope, 18-27, had serum HBV DNA more than 10(5)copies/mL (p<0.001). By multivariate analysis, high level (>10(5)copies/mL) of serum HBV DNA was inversely associated with the presence of mutations in CTL epitopes of HBc (OR: 0.11, p=0.015), while it was directly associated with the presence of promoter double T(1762)A(1764) mutations together with G(1757) (OR: 16.87, p=0.004). CONCLUSION: The inverse correlation between serum levels of HBV DNA and CTL escape mutations of the core protein in HBeAg seroconverted patients, supports the notion that selection of CTL escape mutations consolidates the persistence of HBV infection despite reducing viral fitness.

Improvement of liver function in liver cirrhosis patients after autologous mesenchymal stem cell injection: a phase I-II clinical trial.

BACKGROUND: End-stage liver disease is a medical problem with high morbidity and mortality. We have investigated the feasibility, safety, and efficacy of using autologous mesenchymal stem cells (MSCs) as a treatment. METHODS: Eight patients (four hepatitis B, one hepatitis C, one alcoholic, and two cryptogenic) with end-stage liver disease having Model for End-Stage Liver Disease score > or =10 were included. Autologous MSCs were taken from iliac crest. Approximately, 30-50 million MSCs were proliferated and injected into peripheral or the portal vein. Liver function and clinical features were evaluated at baseline and 1, 2, 4, 8, and 24 weeks after injection. RESULTS: Treatment was well tolerated by all patients. Liver function improved as verified by the Model for End-Stage Liver Disease score, which decreased from 17.9+/-5.6 to 10.7+/-6.3 (P<0.05) and prothrombin complex from international normalized ratio 1.9+/-0.4 to 1.4+/-0.5 (P<0.05). Serum creatinine decreased from 114+/-35 to 80+/-18 micromol/l (P<0.05). Serum albumin changed from 30+/-5 to 33+/-5 g/l and bilirubin from 46+/-29 to 41+/-31 micromol/l. No adverse effects were noted. CONCLUSION: Our data show that MSCs injection can be used for the treatment of end-stage liver disease with satisfactory tolerability. Furthermore, this treatment may improve clinical indices of liver function in end-stage liver disease.

Effects of amino acid substitution polymorphisms of two DNA methyltransferases on susceptibility to sporadic colorectal cancer.

BACKGROUND AND AIM: The present study was designed to consider whether amino acid substitution polymorphisms in O6-methylguanine-DNA methyltransferase (MGMT) and DNA methyl transferase 1 (DNMT1) genes may be associated with the genetic susceptibility to sporadic colorectal cancer. PATIENTS AND METHODS: We assessed eight non-synonymous polymorphisms of these two genes by PCR/pyrosequencing. Our population consisted of 208 individuals with sporadic colorectal cancer and 213 controls. Allele frequencies and genotypes were compared between the two groups. RESULTS: The calculated odds ratios indicated no association between DNMT1 and colorectal cancer. However, there was a significant association between two polymorphisms in MGMT with sporadic colorectal cancer: Arg128Gln (OR, 5.53; 95% CI) and Gly160Arg (OR, 3.04; 95% CI). CONCLUSIONS: These findings could be indicative of factors contributing to high occurrence of Iranian colorectal cancer patients.

Lack of effects of single nucleotide polymorphisms of the DNA methyltransferase 1 gene on gastric cancer in Iranian patients: a case control study.

BACKGROUND: Gastric cancer is one of the most common malignant tumors in Iran. Hypomethylation and/or hypermethylation of DNA has been described in gastric cancer and is presumed to be an early event in carcinogeneisis. OBJECTIVE: We therefore hypothesized that single nucleotide polymorphisms of the DNMT1 gene may be associated with the genetic susceptibility to gastric cancer. METHODS: Totals of 200 patients and 200 controls, both of Iranian origin, were studied. Three polymorphisms were genotyped by PCR-RFLP and allele frequencies and genotypes were compared between the cases and controls. Odds ratios were calculated and the interactions between the polymorphisms, age and sex were examined. RESULTS: There were no significant associations between the DNMT1 polymorphisms and gastric cancer. CONCLUSION: We could not show any association between DNMT1 polymorphisms and gastric cancer. Larger sets of polymorphisms and sample sizes are required for future testing of possible associations.

The frequency of C3435T MDR1 gene polymorphism in Iranian patients with ulcerative colitis.

BACKGROUND AND AIMS: The MDR1 (multidrug resistance) gene, located on chromosome 7, is in one of the inflammatory bowel disease susceptibility loci. It produces P-glycoprotein, a transmembrane efflux pump, transferring drugs and toxins from intracellular to extracellular domains. In the human gastrointestinal (GI) tract, P-glycoprotein is found in high concentrations on the epithelial cells of the colon and small intestine. MDR1 gene polymorphisms such as C3435T are associated with lower P-glycoprotein expression, and thus it is suggested to have an association with ulcerative colitis. We tried to determine the frequency of C3435T polymorphism of the MDR1 gene in Iranian patients with ulcerative colitis and to compare it with a healthy control population. MATERIALS AND METHODS: In this case-control-designed study, 300 unrelated ulcerative colitis patients and 300 sex-and-age-matched healthy controls were enrolled. They were visited at a tertiary center during a 2-year period (2003-2005). DNA of patients and controls was amplified by polymerase chain reaction with specific primers, and C3435T polymorphism was detected by the restriction fragment length polymorphism method. RESULTS: The frequency of the 3435T allele was significantly higher in ulcerative colitis patients compared to the controls (p < 0.001). The frequency of homozygote T/T and heterozygote C/T genotypes were also significantly higher in Iranian patients with ulcerative colitis (p = 0.044 and 0.041, respectively). CONCLUSION: This study suggests that C3435T polymorphism of the MDR1 gene has an association with ulcerative colitis in Iranian population as previously reported in western countries.

Polymorphisms of glutathione S-transferase M1, T1, and P1 in patients with HBV-related liver cirrhosis, chronic hepatitis, and normal carriers.

OBJECTIVES: Persistent hepatitis B virus (HBV) infection often leads to the development of chronic hepatitis and cirrhosis. The role of host genetic factors in chronic HBV infection is not fully understood. We studied the influence of glutathione S-transferase (GST) M1, T1, and P1 polymorphisms in patients with different stages of HBV infections. METHODS: The sample population included 41 HBV normal carriers, 37 patients with chronic hepatitis, and 38 patients with cirrhosis (infected with HBV) compared to a control group (n = 59). PCR-based procedures were performed in the studied populations to confirm the genotypes of GSTT1, M1, and P1. Odds ratio analysis tests were used for statistical evaluation. RESULTS: We found that the frequency of GSTP1-Val (105)/Val (105) genotype was significantly higher in patients with liver cirrhosis (27%) than HBV normal carriers (2.4%; OR 14.8, 95% CI 1.8-122.5) and the frequency GSTP1-Val (105)/Ile (105) genotype was significantly higher in patients with liver cirrhosis (59.5%) than HBV normal carriers (19.5%; OR 6.1, 95% CI 2.1-16.7). The genotype GSTP1-Val (105)/Val (105) was more frequent in patients with chronic hepatitis (19.4%) than HBV normal carriers (2.4%; OR 9.65, 95% CI 1.1-82.8). Patients with cirrhosis also had a higher frequency of the GSTM1 null genotype (71.1%) than HBV normal carriers (27.5%; OR 6.5, 95% CI 2.4-17.4) and the GSTM1 null genotype was more frequent in patients with chronic hepatitis (64.9%) than HBV normal carriers (27.5%OR 4.9, 95% CI 1.8-12.8). The frequency of GSTT1 genotype was similar in all groups. CONCLUSION: These results suggest that in HBV infection, inheritance of the null GSTM1 and GSTP1-Val (105) polymorphisms involves a host genetic factor that is relevant to disease progression.

C77G mutation in protein tyrosine phosphatase CD45 gene and autoimmune hepatitis.

UNLABELLED: Autoimmune hepatitis (AIH) is a rare frequent, multiplex disorder with undefined etiology. Susceptibility to autoimmune hepatitis results from complex interactions between genetic and environmental factors. In this study, we investigated the involvement of C77G mutation in CD45 gene in patients with autoimmune hepatitis among Iranian population by genotyping this mutation in 70 patients and 140 healthy individuals. METHODS: : After amplifying exon 4 by Polymerase chain reaction, we genotyped this mutation with MspI restriction endonuclease among the studied population. RESULTS: : None of the cases with AIH was hetero or homozygote for C77G mutation. Controls had normal genotype except one of them who was heterozygote for C77G mutation. CONCLUSION: : Our results do not confirm the genetic link between C77G mutation and autoimmune hepatitis in Iranian population.

Genotype characterization and phylogenetic analysis of hepatitis B virus isolates from Iranian patients.

Hepatitis B virus (HBV) is one of the major causative agents of acute and chronic liver disease worldwide and is believed to be responsible for a million deaths annually. Eight genotypes of HBV, A to H, have been described on the basis of similarity of the complete genomes sequence. Although, it is reported that the predominant HBV genotype in the Mediterranean area and the middle east is genotype D, there are no reports on HBV genotypes prevalent in Iran. In this study, the C and S regions of HBV from 26 chronic hepatitis B Iranian patients were amplified and sequenced. Phylogenetic analysis revealed that all Iranian HBV isolates sequences were classified into genotype D with bootstrap values of 100%, 73%, and 100% (1,000 replicates each) for S, C, and preS2 regions, respectively. The mean percent intra-distance of S and C regions were 0.8% and 2.3%, respectively. The mean percent inter-distance of S and C regions between Iranians and genotype D isolates were 1.7% and 3.0%, respectively, and the range of mean percent nucleotide distance of S and C regions between Iranians and the other reference isolates were 7.9%-17.5% and 4.8%-14.7%, respectively. Thirteen out of 23 HBV C region sequences showed nucleotide "A" at position 1896 (precore mutant) in C region. Nucleotide 1858 showed presence of "T" in all isolates. No insertion or deletion was found in both regions. SimPlot and BootScanning analyses did not show any recombination between Iranian isolates and other genotypes in both regions.

GSTP1, GSTM1, and GSTT1 genetic polymorphisms in patients with cryptogenic liver cirrhosis.

We investigated glutathione S-transferase (GST) P1 Ile (105) Val, T1, and M1 polymorphisms in 45 patients with documented cryptogenic cirrhosis and 56 healthy control subjects. Polymerase chain reaction-based procedures were performed in the studied populations to confirm the genotypes of GSTT1, M1, and P1. Ile/Val and Val/Val GSTP1 genotypes were more frequent in the patients with cirrhosis (n=39, 87%) than in the control subjects (n=10; 18%) (odds ratio [OR] 34.04; 95% confidence interval [CI] 10.70 to 108.31, P<0.001). Among these patients with cirrhosis, 16 were heterozygous and 23 were homozygous, whereas only one person in the control group was homozygous. The GSTM1 null genotype was also more prevalent in cirrhotic patients than in healthy control subjects (OR 6.83, 95% CI 2.53 to 18.42, P<0.001). The rate of GSTT1 deletion did not show a significant difference between the two groups (OR 2.35, 95% CI 0.76 to 7.28, P=0.111). To our knowledge, this is the first evidence that GSTP1 and GSTM1 polymorphisms may be related to the development of cirrhosis by unknown mechanisms. The significant association of cryptogenic cirrhosis with Val/Val GSTP1 genotype encoding a low detoxification activity protein implicates this polymorphism as a risk factor for the occurrence of the disease.